The need for arrows to clear the bow without undue contact that could disrupt arrow flight is well documented. Most arrow rests now in use provide a way of doing this. Initially the accomplishment of reduced arrow contact with the bow itself was accomplished by adding a “cable guard” attachment to the bow to force the power cables out of the way of arrows passing by. After the arrows fletching cleared the cables, they next had to go by the handle of the bow without making undue contact too. That is where the arrow rests comes into play.
Initially, as far as arrow rests were concerned inventors chose to employ arrow rests with plastic or stiff but resilient piano wire support arms that allowed the arrow fletching to clear the bows handle section. Most employed some combination of springs, pivot mounted spring loaded thin (usually piano wire) wire arrow support arms that retracted to allow free passage of the arrow and then return the support arm to a position ready to accept another arrow being loaded for shooting. These rest types were typically referred to as “flipper” rests. Sometimes the methods for accomplishing these movements used springs, sometimes magnets, sometimes weighted counterbalances. Most such rests required (and still do) a separate attachment to the bow in the area near the arrow shelf of the bow handle to house the rest assembly. Most of these now provide a means of adjusting the rest position up/down and side-to-side.
Keeping the arrow from falling off of the rest when the bow is drawn is another well documented feature of modern-day arrow rests. Arrow rests providing a means of keeping the arrow on the rest are generally called “full-containment” rests. Most such modern-day rests are patterned after the now widely known “whisker biscuit” rest (U.S. Pat. No. 5,896,849) that employ hundreds of thin plastic filaments mounted in a round housing component that surrounds the shaft about 90% of its circumference and leaves just a narrow slot to allow the arrow to be inserted into the desired center of the rest position. These rests require that the arrow fletching push the filaments out of the way as they leave the bow. Fletching and shaft contact is very light, but still present. These rests too generally require a separate attachment to the bow in the area near the arrow shelf of the bow handle to house the rest assembly. Most of these now provide a means of adjusting the rest position up/down and side-to-side.
The latest versions of the “full containment” rests eliminate the filaments and position the arrow shaft on 2-3 smooth contact points which are positioned so as to not make contact with the fletching on the arrow as it leaves the bow.
Recently some arrow rests have employed magnets with biased magnetic field loadings to support the arrow free of any contact with the bow whatsoever when the bow is fully drawn back.
A third category of arrow rests seek to support the arrow during the time the bow is being drawn back, but to then move out of the way completely once the string is released. These types of rests are sometimes called “drop-down” or “fall-away” rests.
Some of the “drop-down” and “fall-away” rests are constructed to function as “full-containment” rests at the same time. Most of these require a separate “timing” cable that connects the arrow rest support component, mounted on the bows riser, to a power cable on the bow to effect timing relating to when the arrow rests “drop-down” feature stops providing vertical support to the arrow shaft. Most of these now provide a means of adjusting the rest position up/down and side-to-side.
Most of the “full containment”, “drop-down”, and “fall-away” arrow rests are constructed of heavy-duty plastics like ABS or carbon filaments, or aluminum, or some combination of these and as such are usually able to withstand some contact with brush and limbs just due to mass and strength of the materials they are made of. Arrow rests using thin and lightweight wire retractable support arms however are typically less robust, having arrow support arms that protrude away from the sight window when not in use (in an extended position) and which are more susceptible to damage from contact with brush, tree limbs etc. when being carried in the field.
As arrow rests evolved to provide more than just a single function (supporting the arrow in a fixed position on the bow) and sought to provide “zero-contact” with the arrows fletching, and “full containment” aimed at disallowing the arrow from falling off of the rest itself, increased durability, and nearly infinite up/down and side-to-side positioning; the arrow rests in general got larger in size, more complex, heavier, more unwieldy, noisier, and much more expensive.
The added weight, especially of the new generation of highly complex arrow rests, being mostly mounted on the back side of the sight window of the bows riser (handle) contributes toward system torque in the assembled condition and will absolutely affect arrow flight just by being mounted on the bow. “System” torque results from the bow, including any attachments to the bow itself, being heavier on one side than the other side or the top half being heavier than the bottom half. The bow moves in the archers hand instantly when the string is released, and “system” torque can adversely affect accuracy, penetration, and trajectory just as limb/pulley torsion does.
Very simple arrow rests for recurve bows 40 years ago, having retractable arrow support arms, typically weighed about 20-30 grains (437 grains is one ounce) and at that weight contributed little to system torque in the bow with such a rest in place. Some current day arrow rests may weigh ¼-⅜ of a pound or more, and weights in that range can seriously disrupt arrow flight due to the added system torque they induce.
Recognition of this unwanted condition led to other inventions (stabilizers that place weights off to the opposite side of the bow, counter-balances, etc.) that are designed to reduce the negative effects on arrow flight of the out of balance condition caused by mounting the complex and heavy arrow rests on the bows handle section.
Kludges on top of kludges so to speak.